TH 700-R4 Odd shift.

Hey guys,
I have a 700 R4 that I put into my 84 Caprice as part of my engine swap project. The tranny came out of an '85 Caprice wagon. It's been rebuilt about 5k ago. Now after getting the fluid back up to the proper level (including a bottle of Lucas Oil), properly adjusting the TV cable, and double checking lines for leaks etc it seems to shift oddly. Under very gentle driving it shifts flawlessly, now too hard, not too soft. But under slightly moderate accelleration it seems to shift too soon and shifts twice so to speak. It does one of two things... one is from 1st to 2nd it shifts, then I feels it shift again but it feels like power is lost on the second shift. The it does the same thing from 2nd to 3rd, but 3rd to 4th is nice. The second thing it sometimes does is the same thing as above, but loses power the first time and regains it the second shift. The engine does not rev up at all during shifts (illusion of shifting into neutral). I'm stumped. It didn't do this when it was in the station wagon. Any ideas? Thanks!

You're stack-shifting. That's a maladjusted TV cable. Fix it now or you will burn it up! If the TV adjusts "properly" yet still does this, adjust it one or two clicks toward the firewall and try not to gun it.

I'll try pulling it back some, but down the road after break in, if I decide to bring the engine at WOT won't the TV cable just be brought right back into the place it's in now? The way I adjusted it was I hooked it up, Pulled it out as far back as it'd go, and by hand move the throttle to WOT and I heard/felt the TV cable snap into place. Was that wrong? It's how I've always done it.

and try not to gun it.
I don't need to gun it for it to act this way, anything above very gentle accelleration it will do this.

What I meant by "try not to gun it" was that once you redid the adjustment, don't "gun it" or the cable will snap back "into adjustment".

Your problem is probably the spring behind the throttle valve inside the transmission. I'd get it fixed, making sure the entire TV system is up to spec.

I'll have to get it checked out professionally then. That way I know it's right. Well, I can at least assume it's right.

In addition to verifying the pressure control (TV), you might want to consider draining the trans and refilling to get the oil additive out of there. You can thank me later when it starts to shift normally again. Viscosity and friction modifiers in a THM transmission are not a good thing. If you only did it with the intent of prolonging the transmission life, change to synthetic ATF instead.